Drawing mechanism for textile rovings



Aug. 17 1926.

F. CASABLANCAS DRAWING MECHANISM FQR TEXTILE ROVINGS Filed August 18, 1922 2 Sheets-Sheet, 2

@l www `M l' Patented Aug. 17, .19.26.,

UNITED STATESy FERNANDO cAsABLANcAs, or SABADELL, SPAIN.

DRAWING MECHANISM FOR TEXTILE EOVING.

Application led August 18, 1922, Serial No. 582,722, and in'Spain September 10, i921.

M invention relates to the drawing of textile materials and more particularly to a drawing mechanism adapted to effect on the roving two or more successive drawings in a single machine.

In my co-pending patent application Ser. No. 472,453 there is described a drawing mechanism for textile rovings in which there are combined feeding devices of the types employed for permitting large drawings, which feeding devices are so arranged that in addition to the usual movement for bringing the roving very close up to the line of contact of the drawing rollers, they possess a rotary movement around the axis of the roving for the purpose lof communicating thereto an accidental or false twist; This arrangement is specially suitable for giving to the roving two or more/successive drawings, the apparatus being so arranged that th'e iirst drawing is eHected in a drawing lmechanism of any type and the second one in a mechanism in which the feeding devices, in addition to the feedin movement, have a rotary movement around the roving in order to communicate to it a twist and at the same time, convey the roving to the drawing rollers. In this manner the roving after it has undergone the rst drawin rec'eives a twist which reunites all its bres and diminishes its diameter thereby causing it to remain in good condition for the purpose of undergoing the second drawing.

This already known mechanism yields good results but has two disadvantages' inl practice. In the rst place the construction of the drawing apparatus is rendered very complicatedV owing to the necessity of giving to th'e feeding devices the double movement which produces the advance of the roving and the torsion of the same, and in consequence thereof the working of the mechanism is always rendered delicate. In the second place as 7the feeding devices which permit large drawings accompany the roving up to a point which is distant from the line of contactof the drawing rollers by less than the mean length 'of the bres and on the other hand the false twist extends up to the point at which the feeding devices quit the roving, the result is that the second drawing is elfected in an extension of the roving one part of which is untwisted and the other part twisted and this in certain cases is a disadvantage in order to obtain p a perfect drawing.

These disadvantages are obviated by the drawing mechanism which forms the subject matter of the present invention, in which there is also given to the roving an accidental or falsetwist between the two drawings, but which is distinguished from the mechanism already known by the fact that the feeding devices 'of the second drawing set do not effect any more movement than device Abetween two drawing sets or mechanisms. In this way as the roving quits the drawing rollers of the first drawing set, it 1s subJected to a twist which diminishes its diameter and reunites all its fibres in such a way that when the roving is drawn in the second drawing set its width or diameter has already been considerably reduced and a relatively large drawing can be obtained without the risk of the fibres of the roving losin their cohesion and becoming separate which would cause irregularities in the yarn. v

As the 'roving is completely untwisted when it enters the second drawing set, it is convenient that the latter be such as to permit of large drawings, that is to say, that it is provided with feeding devices which accompany the roving up to a point which is distant from fthe drawing rollersA by a distance which is less than the mean length of the fibres. In this way any irregular slip of the fibresin the roving which is being drawn and separation lof the said fibres therein during the second drawing is avoided and consequently the considerable irregularities which the said slip and separation produce in the yarn are avoided also.

, These feeding devices may be, constituted by belts, cylinders of small diameter, combinations of a belt with cylinders or with plates, etc.

The accompanying drawing shows diagrammatically in transverse sectiontwo constructional examples of the drawing mechanism of the present invention. `In the y the drawing rolllers. -4-, -5-.

example shown in Figure 1 the second drawing set as as feeding devices endless belts. In the c se of Figure 2 the second drawing set has as feeding devices cylinders of small diameter arranged. close up to the drawing rollers.

The apparatus shown in Figure 1 has two drawing sets the first of which is constitutedk by the feedgrollers -40, -41. The intermediate rollers -6,-, -7- and The second drawing set is constituted by the feeding belts 31-, and the drawing cylinders 8, -9-'. The cylinder 4lisv of large diameter in order that its weight alone may exert a sufficient pressure on the roving fibres formin B3- and the drawing roller '-5- is loaded in the usual way by means of a curved opening 62- for the introduction of the roving and having a point 63- with a helical groove for imparting theftorsion tol grasping' it with the hand- The peripheral speed of the feeding ded vices-31- S2- only requires to Abe rod -3- from which hangs a weight (not Vgreater than that of the drawing rollers shown Vin the drawing). In the second drawing set both the rollers Q5- and. 9- are loaded by means of the weighted rod -3- and the pressure device. -2- which communicates to the two rollers the pressure exerted by the weight.

-4-- -5- to the extent necessary for the vroving to be permanently stretched between both devices. Notwithstanding, in the majority of cases a better result is obtained if the speed of the feeding devices is substantially greater than that of the drawing The feeding belts .31.-, -32- arranged rrollers -4-, '5- in such a way that there in the usual way are driven by the rollers -25., 26- and convey lthe fibres of the roving to a point situated relatively very close to the drawing rollers, 8 and -9.

Between the drawing rollers -4 5-4 of the first drawing set and the feeding belts -31, 32- of the second drawing se't is arranged the false torsion device 60 which communicates to the roving-an accidental or false twist at the section between the rollers 4, -5- and the point 63- of the device -60-. On emerging from the drawing rollers -4- -.\5- and due to the drawin which they have just undergone, the tigres of the roving are in an untwisted state and desintegrated or separated from each other, but the accidental twist given by the device -60- reunites al1 the a roving of smaller width or diameter, t us avoiding that between the drawing rollers -4- 5 and the feeding belts -31- -32- the fibres may drop out of the roving and cause irregulamties in the arn. y This reduction of the diameter 'of the roving augments the cohesion of the fibres with each other and prepares the roving to undergo the second drawing in the next drawin set,l thus avoiding any separation of the bres in this second drawing.

The false torsion device '-60- may be' of any suitable type which can be driven or operated 1s the usual way. In Fi ures 1 and 2 is shown as an example a fa se torsion device which is specially suitable for application to this mechanism; It is constituted by a 'member 60- approximately of funnel shape provided with a split or is produced between these rollers and the feeding devices 31 -32- a certain dra-wing of the roving while it is being subjected to the false twist. This drawing with the simultaneoustwist contributes to the better arrangement in parallel of the fibres and to the regularization of the yarn because the twist accumulates at the arts of smaller diameter of the roving. an increases the resistance of these parts to the drawing by which the drawingis effected preferabl at `the more bulky parts of the roving w ich decrease in size untilvthey become equalized withthe other.

The feeding devices of the second drawing set may be of any suitable t pe provided that they be of a type of feed evices which permit of large drawings because as the roving issues from the drawisg rollers without any torsion it is necessary that the feeding devices accompany the said roving up to a point which is distant from the drawing rollers by an amount which is `less than the mean length of the fibres.

In Figure 2 is shown an example of construction is which these feeding devices are constituted simply by two rollers -54-, -55- of small diameterl arranged very close to the drawing rollers -8- -9. The lower roller -55- receives movement in any usual way and theupper roller -54 rests on the lower one by its .own weight and as this is small, the pressure which this roller exerts on the libres is also small and consequently allows the fibres driven by the drawing rollers to slip between the rollers In order to avoid the-unequal wear of the rollers and beltsit is convenient to4 com -A ss 'i municate to the roving a transverse to and fro movement in the well known way by means of the bar -57- and in this case the false torsion device is provided with the same to and fro movement as the bar -57-. This may be secured bymounting the supports of thel false torsion devices on a bar which slides in convenient guides and by coupling this bar with the bar -57.

The belts 31 and 32 in Figure v2 are of course in practice provided with guides to maintain these belts in the shape shown. These guides form no part of the present invention and they have been omitted to avoid complicating the illustration and in the interest of clearness. Such guides may be seen in Figure 3 of applicants prior Patent No. 1,213,744, granted January 23, 191

The positive drive for the cylinders 26 and 55 has also been omitted for clearness and because of the fact that this forms no part of the present invention. Such a drive means is shown in the U. S. Patent to Cesoni, et al, No. 1,459,572, granted June 19, 1923.

I`n Figure 1 the cylinder 26 is shown as being positively driven by the friction .wheels 100 and 101, the wheel 101 being driven from an appropriate source of power.

Inl Figure 2 the cylinder 55 is shown as being driven by similar friction wheels 102 and 103'.

I claim:

1. A large draft apparatus for drawing textile rovings composed of an initial drawing mechanism for giving the roving a pri-` mar or initial draft, twisting means for receiving the roving proceedin from the initialdrawing mechanism 'an communieating. a false twist to this roving, and a final drawing mechanism for effecting a final draft of the roving after vthis latter-has passed through the twisting` head, said final drawing mechanism being provided with .feeding'means positively driven, which compel the roving to advance and accompany it' upv quite close to the drawing rollers of said final drawing mechanism.

`2. A large draft apparatus for drawing textile rovings -which comprises an initial drawing mechanism composed of several pairsl of rollers, a twisting head for receivmg the roving coming from the initial drawing mechanism and communicating to it a .false twist, and a final drawing mechanism formed by feeding means which receive the roving coming'from' the false twist device and a pair of drawing rollers which give the final draft to the roving held by said feeding means, said Ifeeding means communicating to the roving an advancing movement towards the drawing rollers and accompanying it up to a point quite near the said drawing rollers.

3. A large draft apparatus for drawing textile rovings which comprises an initial drawing mechanism formed by several pairs of rollers, a twisting head which receives the roving coming from the initial drawing mechanism, and a final drawing mechanism which receives the roving coming` from the ltwisting head and gives it the final draft,

said .final drawing mechanism -being composed of a pair of endless feeding bands, positively driven, which receive the roving from the twisting head and cause it to advance towards the drawing rollers accompanying it up quite close to these drawing rollers and a pair of drawing rollers which receive the roving delivered by the feeding bands and give it the final draft.

4. A` large draft apparatus for drawing textile rovings which comprises an initial drawing mechanism formed by several pairs of rollers which revolve with increasing peripheral speeds, a twisting head which receives the roving coming from the initial drawing mechanism and communicates to it a false twist, and a final drawing mechanism which receives the roving coming from the twisting head and gives it.' the final draft, said final drawing mechanism being composed of a pair of endless feeding bands,

higher than the speed of the last pair of lrollers o f the initial drawing mechanism and a pair of drawing rollers which'seize the roving conducted by the said feeding bands and give it a draft, said feeding bands moving in such a way that they hold the roving between them and compel it to advance towards the drawing rollers vand accompan it up to a point quite close to the said drawing rollers. Y

In testimony whereof I have signed my name to this specification.

FERNANDO CASABLANCAS. i 

